Dirty Father Thames: More an open sewer than a river, the disgusting state of the Thames in London in 1849, the year of the Great Stink when Parliament was suspended because of the smell. Punch, London, 1849 / UniversalImagesGroup / Getty Images

Every city has its drawbacks -- parking, for example, or crime, or the price of a decent pizza slice -- but in the 1800s London faced a particularly unusual and disgusting problem: the city literally stank. And this wasn't an occasional whiff of urine or hot garbage from an alleyway, oh no. Instead, a pervasive stench permeated the area, an odor so strong that it disrupted Parliament, forcing the government to take action (and eventually rewriting our understanding of disease in the process).